The Engineering Method

The Engineering Method Based on “Discussion of the Method” by Billy Vaughn Koen ENGR 1310 Introduction to Engineering

What is an Engineer? • An Engineer is not defined by her product • Nano-robots • Airplanes • Embedded Computers • An engineer is defined by her method • Finding the best change • Using available resources • In an environment of uncertainty

“To Engineer” • The clergy in Iran engineered the firing of the president. • The chessmaster engineered a perfect countermove. • The general engineered a coup d'état without the loss of life.

Why is Engineering Such a Mystery? • The Scientific Method • Well-understood, even by the layperson. • “Science is theory corrected by experiment.” • All variables held constant except one. • “Answer in the back of the book.” • Extensively analyzed by philosophers • None of these are true for the Engineering Method • Although engineers often employ science and scientific reasoning

Four Key Elements of Engineering Problems: • Change: the situation requires a change. • Best: the best change is desired... • Resources: using the available resources. • Uncertainty: knowledge about the situation is incomplete and sometimes inconsistent

Change A Measure of Change B time

Change • Four practical difficulties in getting from A to B: • Engineer lacks complete knowledge of the world at A • The exact final state, B, is unknown and cannot be anticipated • There is no single path from A to B • Engineering goals can change during the process (the location of B floats!)

Change • Is all change caused by engineers good? • What about unintended consequences? • Aswan High Dam in Egypt • Can you name any others? • Can you think of any engineering disasters? • Tacoma Narrows Bridge, WindBelt • Kansas City Hyatt Regency • Chernobyl Nuclear Power Plant in U.S.S.R.

The Final State (B) Cannot Be Fully Known!

Unintended Consequences • Increased salinity of the Nile by 10% • Led to collapse of sardine industry • Caused Coastal Erosion • Displaced 100,000 Nubians • Drastically altering their way of life • BUT provides ½ of Egypt’s electrical needs

Best • Best for whom? • Westerners are conditioned to accept Plato’s notion of the Ideal • A new concept of “best” • Optimization theory • The Optimum compromise • Apollo Program • Leapfrog learning • Political vs. Economic tradeoffs

Television Example: Best • Consider a television with only one knob: • Increased knob setting results in sharper picture, • Increased knob setting also results in worse sound.

Television Example: Best Assuming Picture and Sound are Equally Weighted

Television Example: Best With Picture is half as important as Sound (for a person with hearing problems)

Available Resources • Tangible Resources • Money available for project • Time to complete project • Raw materials like steel, concrete, silicon • Computer resources • Number and education of engineers • Intangible Resources • Past experience with similar projects • Engineer’s interests, passions, etc.

Time as a Resource • Problem: estimate number of ping-pong balls that can fill the room in • 60 seconds • 2 days • Unlimited time • Each time limit defines a new engineering problem because the time resource is different • Each solution would be valid from an engineering point of view because it was done within the time constraints imposed.

Uncertainty • Engineers are asked to find a solution to a problem while lacking complete information • In Change: both the starting and ending points (A & B) are not fully known • Resources: intangible resources cannot be quantified, yet they affect the outcome • Best: the best design is not always clear, best for whom?

What is an Engineer? • An Engineer is not defined by her product • Electrical Engineer • Computer Engineer • Mechanical Engineer • An engineer is defined by her method • Finding the best change, using available resources in an environment of uncertainty • Engineering Degree great training for… • Business, Medicine, Law, Politics, Development

The Engineering Method